The world renowned physicist passed away on Wednesday (14.03.18) morning at the age of 76, and now Eddie - who portrayed Stephen in the 2014 movie 'The Theory of Everything' - has paid tribute to the star in a touching statement.
He said: ''We have lost a truly beautiful mind, an astonishing scientist and the funniest man I have ever had the pleasure to meet. My love and thoughts are with his extraordinary family.''
Eddie picked up the Oscar, Golden Globe, and BAFTA awards for Best Actor for his role in the movie - which followed Stephen's rise to fame and relationship with his first wife, Jane - and in a post on his Facebook page after the release of the production, the Professor himself praised Eddie's work.
He wrote at the time: ''I thought Eddie Redmayne portrayed me very well in The Theory of Everything Movie. He spent time with ALS sufferers so he could be authentic. At times, I thought he was me.
''Seeing the film has given me the opportunity to reflect on my life. Although I'm severely disabled, I have been successful in my scientific work. I travel widely and have been to Antarctica and Easter Island, down in a submarine and up on a zero gravity flight. One day I hope to go into space.
''I've been privileged to gain some understanding of the way the universe operates through my work. But it would be an empty universe indeed without the people that I love.''
Stephen was told he had just two years to live at the age of 21 when he was diagnosed with Amyotrophic Lateral Sclerosis (ALS) - also known as Lou Gehrig's disease - which confined him to a wheelchair and left him unable to speak except through a voice synthesiser.
The scientist managed to live well beyond the life expectancy placed on him by the disease - which causes the death of neurons controlling voluntary muscles - and went on to do groundbreaking scientific research on black holes and relativity.
He is perhaps most known for his best-selling book 'A Brief History of Time', which explained the mysteries of the universe in basic terms and sold over 10 million copies worldwide.
Stephen's family confirmed the news of his passing on Wednesday in a statement which read: ''We are deeply saddened that our beloved father passed away today. He was a great scientist and an extraordinary man whose work and legacy will live on for many years.
''His courage and persistence with his brilliance and humour inspired people across the world. He once said, 'It would not be much of a universe if it wasn't home to the people you love.' We will miss him forever.''